M.Sc. Joshua Steyer

B.Sc. Zhiwei Guo

Motivation
The heart can be considered as an excitable medium governed by excitation waves that result in the muscle contraction. Cardiac arrhythmias are caused by an abnormal propagation of these waves and we therefore aim at a thorough mechanistic understanding the behaviour of different sorts of wave patterns using computer models. In computer models of the heart, both space and time are discretised and state-of-the-art simulations usually use computational elements, which average over several hundreds of myocytes (homogenisation). However, it has been shown that also the electrophysiology on a sub-cellular scale plays a significant role for the initiation of arrhythmias. Thus, using such high-resolution models need to be considered as well.

Thesis Topic
 We are working with the so-called extracellular-membrane-intracellular (EMI) model [2], which explicitly represents the myocytes and the surrounding bath in the mesh to understand the microstructural behaviour of the excitation waves in the heart. The thesis project is intended to characterise different sorts of excitation patterns within this model. We want to place a special focus on fibrotic tissue for which there are different approaches to model it and compare these different approaches in the sense of analysing how they translate (differently, if at all) to excitation patterns.
We will make use of Kaskade7, which is an in-house software provided by the ZUSE Institute Berlin that solves the complex differential equations governing the electrophysiology. To do so, we will work together with Dr. Tomáš Starý.